Christopher Lee Carlson was indicted on two criminal counts after an investigation into approximately 100 envelopes that were mailed that contained white powder. All of the letters, which were postmarked Portland, Ore., tested negative for anthrax or any other toxic substances, Associated Press reports.
Carlson was charged on Friday by a federal grand jury after being arrested at his home in the Portland area. Carlson allegedly mailed a threatening communication to House Speaker John Boehner (R-Ohio) and mailed a letter that threatened to use a biological weapon to U.S. Sen. Barbara Mikulski (D-Md.).
Carlson will be arraigned on Monday.
More than 100 letters were sent in total that were addressed to U.S. representatives and senators.
“Threatening letters – whether hoax or real – are serious concerns that federal law enforcement agencies will aggressively pursue,” Greg Fowler, the special agent in charge of the FBI in Oregon, said, according to Associated Press.
The sender said that he wanted to end corporate personhood, end corporate lobbying and money, and start a new constitutional convention. The letters had a fake return address from a sender calling himself “the MIB.”